Simultaneously Boosting Thermoelectric and Mechanical Properties of n-Type Mg₃Sb_1.5Bi_0.5-Based Zintls through Energy-Band and Defect Engineering

Yu, Lu1; Shi, Xiao-Lei2,3; Mao, Yuanqing2,3,4,5,6; Liu, Wei-Di2,3; Ji, Zhen1; Wei, Sitong1; Zhang, Zipei1; Song, Weiyu7; Zheng, Shuqi1; Chen, Zhi-Gang2,3

2024-01-02

10.1021/acsnano.3c09926

ACS NANO   影响因子和分区

1936-0851

1936-086X

Incorporating donor doping into Mg3Sb1.5Bi0.5 to achieve n-type conductivity is one of the crucial strategies for performance enhancement. In pursuit of higher thermoelectric performance, we herein report co-doping with Te and Y to optimize the thermoelectric properties of Mg3Sb1.5Bi0.5, achieving a peak ZT exceeding 1.7 at 703 K in Y0.01Mg3.19Sb1.5Bi0.47Te0.03. Guided by first-principles calculations for compositional design, we find that Te-doping shifts the Fermi level into the conduction band, resulting in n-type semiconductor behavior, while Y-doping further shifts the Fermi level into the conduction band and reduces the bandgap, leading to enhanced thermoelectric performance with a power factor as high as >20 mu W cm(-1) K-2. Additionally, through detailed micro/nanostructure characterizations, we discover that Te and Y co-doping induces dense crystal and lattice defects, including local lattice distortions and strains caused by point defects, and densely distributed grain boundaries between nanocrystalline domains. These defects efficiently scatter phonons of various wavelengths, resulting in a low thermal conductivity of 0.83 W m(-1) K-1 and ultimately achieving a high ZT. Furthermore, the dense lattice defects induced by co-doping can further strengthen the mechanical performance, which is crucial for its service in devices. This work provides guidance for the composition and structure design of thermoelectric materials.

thermoelectric Zintl doping defect mechanical performance

SCI ; EI

英语

其他

Australian Research Council[51871240]

Chemistry ; Science & Technology - Other Topics ; Materials Science

Chemistry, Multidisciplinary ; Chemistry, Physical ; Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary

WOS:001144011000001

AMER CHEMICAL SOC

Web of Science

1.China Univ Petr, Coll New Energy & Mat, Beijing 102249, Peoples R China
2.Queensland Univ Technol, ARC Res Hub Zero Emiss Power Generat Carbon Neutra, Sch Chem & Phys, Brisbane, Qld 4001, Australia
3.Queensland Univ Technol, Ctr Mat Sci, Brisbane, Qld 4001, Australia
4.Univ Queensland, Sch Mech & Min Engn, Brisbane, Qld 4072, Australia
5.Southern Univ Sci & Technol, Dept Phys, Guangdong Prov Key Lab Computat Sci & Mat Design, Shenzhen 518055, Peoples R China
6.Southern Univ Sci & Technol, Guangdong Prov Key Lab Computat Sci & Mat Design, Shenzhen 518055, Peoples R China
7.China Univ Petr, Coll Sci, Beijing 102249, Peoples R China

Yu, Lu,Shi, Xiao-Lei,Mao, Yuanqing,et al. Simultaneously Boosting Thermoelectric and Mechanical Properties of n-Type Mg₃Sb_1.5Bi_0.5-Based Zintls through Energy-Band and Defect Engineering[J]. ACS NANO,2024,18(2).

Yu, Lu.,Shi, Xiao-Lei.,Mao, Yuanqing.,Liu, Wei-Di.,Ji, Zhen.,...&Chen, Zhi-Gang.(2024).Simultaneously Boosting Thermoelectric and Mechanical Properties of n-Type Mg₃Sb_1.5Bi_0.5-Based Zintls through Energy-Band and Defect Engineering.ACS NANO,18(2).

Yu, Lu,et al."Simultaneously Boosting Thermoelectric and Mechanical Properties of n-Type Mg₃Sb_1.5Bi_0.5-Based Zintls through Energy-Band and Defect Engineering".ACS NANO 18.2(2024).